This is so that use of symbols referenced in these asm()-s can be properly tracked by the compiler, just like is the case for all other asm()-s. I'm particularly looking forward to use this in the Linux kernel. It is certainly not very useful in PIC code, at least not with some extra care.
Changes from the original posting (over a year ago) are the splitting into two parts (first separating out LTO's writing of top level asm nodes, then doing the change actually intended here) and one or two problems fixed in the LTO code. Jan
